impact of topographic and atmospheric masses over iran on validation and inversion of goce gradiometric data

the dedicated satellite mission goce will sense various small mass variations along its path around the earth. here we study the effect of the earth’s topography and atmosphere on goce data. the effects depend on the magnitude of topographic height, and they will therefore vary by region. as the effect of the atmosphere and topography must be removed from the total gravity anomaly prior to geoid determinations, these effects should also be removed to simplify the downward continuation of the goce data to the sea level. the main goal of this article is to investigate the direct topographic and atmospheric effects in a rough region like iran. maps of the direct effects and their statistics are presented and discussed. numerical results show maximum direct topographic and atmospheric effects on the goce data can reach 2.64 e and 5.53 me, respectively, when the satellite flies over iran. the indirect effect of the atmospheric and topographic masses are also formulated and presented.